EXAMPLE 1

Starting from the Wulff shape, the exact evolution is known.

We can compute the error to show that Allen-Cahn approach is consistent with crystalline evolution.
BUT computation is very heavy (days on a Digital ALPHA 500 workstation) and we couldn't reach the asymptotic regime.
Still work to be done: implicit scheme, adaptation, stretched elements,...
3 parameters to control: epsilon, h, tau.

Initial shape

Exact solution at times:
0, 0.04, 0.08, 0.12, 0.16, 0.20, 0.24, 0.25